English

Stabilizing randomized GMRES through flexible GMRES

Numerical Analysis 2026-05-11 v2 Numerical Analysis

Abstract

We explore the use of flexible GMRES as an outer wrapper for sketched GMRES. Building on a new bound for the residual of FGMRES in terms of the residual of the preconditioner, we derive a practical randomized solver that requires very little parameter tuning, while still being efficient and robust in the sense of generating non-increasing residual norms.

Cite

@article{arxiv.2506.18408,
  title  = {Stabilizing randomized GMRES through flexible GMRES},
  author = {Stefan Güttel and John W. Pearson},
  journal= {arXiv preprint arXiv:2506.18408},
  year   = {2026}
}
R2 v1 2026-07-01T03:29:02.206Z